When baker's dough is mixed, usually it is blended in a large mixer and the batch of dough developed in the mixer is at a density of approximately 69 pounds per cubic foot. The dough must be transferred from the mixer to a stuffing pump and the stuffing pump progressively pressurizes the batch of dough to form the dough into a stream that moves through subsequent dough handling equipment, such as a metering pump, a dough distribution manifold, a dough divider, and onto the surface conveyor of a rounder bar system. Once the dough has been mixed, the dough begins to develop CO2 and expand or "rise" as it ages, and as the dough is being handled by the prior art stuffing pumps and subsequent processing equipment leading to the dough divider, the dough is sheared, torn, stretched, held in elevated pressures and otherwise handled in a manner that tends to deteriorate the gluten structure of the dough. Maintaining the gluten structure is essential in providing a final product which has uniform grain structure. Therefore, it is important in the handling of the stream of pressurized dough that the dough not be unnecessarily stretched, torn or sheared and held at elevated pressures.
Preferably, the stream of pressurized dough should pass through as few constrictions and changes of direction as is practical so as to avoid tearing, stretching and shearing and to avoid the requirement of high pressure to transport the dough and to avoid large pressure drops. Further, it is desirable to maintain the dough under high pressure for as short a period of time as is practical so as to avoid deterioration of the dough.
A common practice for subdividing a stream of baker's dough moved by the stuffing pump of a dough handling system has been to move the stream of dough into a common manifold and exhaust the dough from several outlet ports of the manifold into separate conduits and to deliver the dough from the several conduits to a dough divider that continually slices each subdivided stream into dough balls. One of the major problems with the prior art systems is the accurate control of the dough as it moves through the manifold and to the dough divider. It is important that the dough be delivered through each conduit to the dough divider at substantially equal masses so that when the streams of dough are separated into dough balls by the dough divider, each dough ball will be of a predetermined mass that is suitable for subsequent rounding, proofing and baking, to yield baked products all of which are of uniform size, shape, consistency and weight.
The method practiced by the prior art generally comprises the installation of valves in each conduit leading away from the dough distribution manifold toward the dough divider. When the operator of the system detects too much or too little dough moving through one of the conduits, the valve for that conduit is adjusted to adjust the dough flow through the conduit. For example, when a valve is moved more toward its closed position to further constrict the passage of the conduit, the rate of dough moving from the manifold through the conduit to the divider decreases and the back pressure of the dough stream leading toward the valve increases, which leads to increased back pressure in the distribution manifold and in the adjacent ones of the other discharge conduits. Usually, this causes an increased flow through the adjacent conduits but not through the remote conduits. Therefore, in order to adjust the flow of dough through one conduit, the system operator usually is required to adjust the valves of at least the adjacent conduits, and possibly others of the valves of the distribution system. Further, the presence of so many valves to control the system increases the constrictions in the flow paths of the dough and therefore increases the amount of pressure required to drive the system. Further, the placement of valves in each delivery conduit where the cross-section of the dough is relatively small generally functions to require a relatively high pressure drop across the valve, thereby requiring increased back pressure to force the dough past all of the valves, and comprises a constriction in each dough path that causes the dough to change shape and direction of movement.
An example of a prior art dough stream control system is found in U.S. Pat. No. 4,948,611 which teaches that it is essential that each of the dough streams be fine tuned as to the constant velocity of dough by means of throttling valves in each delivery conduit.
In addition, the typical prior art dough distribution manifolds require the dough, and therefore the gluten strands that are interconnected throughout the dough mass, to be torn apart as the dough is divided from one inlet stream into several outlet streams to the dough divider. The tearing of the gluten strands causes the gluten deterioration at the point of rupture as well as requiring greater back pressures to provide the energy to tear the strands. The higher required pressures cause the gluten to age rapidly and increases the dough temperature, the first result causing a deterioration of final product quality and the second making it more difficult to "machine" (round, shape and mold) the final dough ball.
Finally, it is important that all of the dough in the final product proceed through a uniform environment during dough processing, proofing and baking phases. As shown by the cited prior patent, the prior art dough distribution manifolds require the dough to proceed from the entrance of the manifold different distances to the outlets of the manifold and along conduits of differing lengths and varying back pressures and varying residence times to reach the dough divider. The result is a significant variation in product from the outlets of the different conduits.
Therefore, it can be seen that it would be desirable to provide a distribution system for baker's dough that separates the stream of dough leading from the stuffing pump toward the dough divider into a plurality of dough streams that are of equal mass and velocity and with lower driving pressure and lower pressure drop of the dough as the dough moves through the system.